A retrospective cohort study was undertaken in a predominantly Black population undergoing standard treatment for lupus nephritis (LN) to estimate the incidence of, and risk factors for, complete response (CR) according to modified Aspreva Lupus Management Study (mALMS) and modified Belimumab International Study in Lupus Nephritis (mBLISS) criteria by 12 months. Patients with biopsy-proven LN class III or IV ± V, urine protein-to-creatinine ratio of ≥1gm/gm and estimated glomerular filtration rate of >50 ml/minute/1.73 m2 at the time of the incident LN flare were included. The clinical, treatment, and laboratory factors associated with CR were identified using multivariable Cox regression. Of 173 patients, 86.1% were women, 77.5% were Black, and over half (59.5%) had non-commercial insurance. By 12 months, 20.6% (95% confidence interval (95% CI) 14.6-28.6%) achieved mALMS CR and 33.7% (95% CI 26.4-42.4%) achieved mBLISS CR. Factors associated with mBLISS CR were commercial insurance (adjusted CR ratio=3.5 [95% CI 1.9-6.7]; P < 0.001), albumin (adjusted CR ratio=1.8 per 1 gm/dl increase in albumin; P=0.02), and low C4 (adjusted CR ratio=2.6; P=0.03). Cumulative incidence of end-stage renal disease (ESRD) at 3 years was 23.1% (95% CI 15.7-31.3%) and 6.1% (95% CI 2.8-11.1%) for death. Patients with non-commercial insurance were more likely to develop ESRD, with cumulative incidence of 30.4% (95% CI 19.6-41.9%) compared to 12.7% (95% CI 5.0-24.2%) for patients with commercial insurance (P=0.024). In a primarily Black, uninsured LN population, despite achieving similar CR rates at 12 months, the incidence of ESRD and death exceeded those observed in controlled clinical trials with placebo arms.
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